Maze Polypores

Welcome back to Mushroom Monday, your weekly look at some of PEI’s fascinating fungi. The dry weather has made it a poor year for most mushrooms, but you can still find the tough Polypores. Here’s a new one to add to our list: Thin-walled Maze Polypore (Daedaleopsis confragosa).

Polypores get their name from the many tiny holes (pores) under their caps. Those holes are the ends of tubes that are lined with the mushroom’s spores. Maze Polypores are distinctive in that their pores are elongated into a maze-like pattern which makes this group easy to identify (main photo).

Thin-walled Maze Polypore is also known as Blushing Bracket because, on fresh specimens, the pores turn a pinkish colour when bruised. (In the top right photo, note the blush-like bruising on the outer half of the fungus where I grabbed it to remove it from the tree). The top of the cap has concentric rings in various shades of brown or tan when fresh (top right), becoming pale as the mushroom ages (bottom right).

Thin-walled Maze Polypore is one of the white rot fungi, digesting lignin and leaving behind bits of cellulose (a carbohydrate) that can be used by nitrogen-fixing bacteria and wood-eating invertebrates. White rot fungi are ecologically important, contributing to healthy soils, available nitrogen, nutrient cycling, and biodiversity. As decomposers, they also keep us from being surrounded by piles of undecomposed dead things!

Like the Dyer’s Polypore we looked at last week (https://www.pei-untamed.com/post/dyer-s-polypore), Thin-walled Maze Polypore has been used to create fabric dyes, producing shades of yellow, beige, and light brown depending on the process used.  It’s too tough to be edible but has been the subject of medical research into potential antibacterial, antifungal, antioxidant, and anti-tumour properties, as well regulation of blood sugar, with some promising results.

This is one of the most frequently-reported fungi on the Island, likely because it’s both common and easy to identify. It grows on dead hardwood trees – often Birch, Cherry, and Willow – which helps to differentiate it from the Conifer Mazegill (Gloeophyllum sepiarium) found on softwoods.  Thin-walled Maze Polypores fruit in late summer and fall, but you can often find last year’s brackets still attached to their trees.

If you find a Maze Polypore growing on Birch, it’s worth taking a closer look. The very-similar Daedaleopsis septentrionalis may be present on the Island, though this has not yet been fully confirmed. Unlike Thin-walled Maze Polypore that’s found on a range of hardwoods, D. septentrionalis is exclusive to Birch. From above, the two fungi are nearly identical; underneath, the pore surface of D. septentrionalis is less maze-like, and looks more like a series of tuning forks.

 As a final note, fellow fans of Greek mythology may have noticed the similarity of this mushroom’s scientific name to Daedalus, who not only played a role in creating the Minotaur of Crete but also built the labyrinth that imprisoned it. The labyrinthine pattern on the undersurface of this group of Polypores inspired mycologists to name the genus Daedaleopsis.

Thin-walled Maze Polypore is one of the many beautiful examples of geometry in nature on PEI Untamed!